(1) Field of the Invention
The present invention relates generally to computer systems and, more particularly, to an interface between a computer and input devices in communication with the computer over wireless links.
(2) Description of the Prior Art
Various computers and microprocessor-based devices and systems provide one or more user input devices to allow a user to control certain operations. Such an input device may be separated from the host computer or device and thus a communication link and an interface may be implemented to support proper communications between the input device and the host computer or device. Generally, each of the input device and the host computer/device includes appropriate software and hardware for the communication link and interface.
For example, a typical desk top or laptop computer may have a keyboard and a pointing device for a user to input data or commands for controlling or operating the computer. Examples of the pointing device for computers include a mouse, a touch pad, a trackball, and a pointing stick (IBM laptops). In addition to keyboards and pointing devices, examples of some other user input devices include joysticks and game pads for computers and microprocessor-based game machines, control units for other microprocessor-based devices. In general, a user uses an input button, a control stick, one key or a key combination, or a combination thereof to input data or a command. Circuitry in the input device converts the input data or command into a proper form for transmitting to the computer or device.
Such an input device generally uses a particular communication link to transmit the input data or command to the computer or device. An input device may be a wireless input device using a wireless communication link or a wired link using an electrical cable. Input devices with wired links may be implemented based on PS/2 keyboard interface, USB 1.0 and USB 2.0 and other interfaces. The wireless communication link may be implemented by a radiation transmitter to send the input to a corresponding radiation receiver at the computer or device. Many wireless input devices use RF radiation links based on different radio interfaces such as IEEE 802.5.14 for low speed links and wireless USB 2.0 and IEEE 1394 for relatively high speed links. Some of these wired or wireless input devices may use the Human Interface Device (HID) protocol over wired or wireless USB links or other non-USB communication links.
Wireless input devices beneficially increase the flexibility of the interaction between a user and a host computer in that no wired connection is required with the host computer. However, given that a wired connection generally provides a source of power for an input device, wireless input devices are required to be self-powered (e.g., battery-powered). Unfortunately, batteries used to power existing wireless input devices typically last for a period of time significantly less than the useful life of such devices. As a consequence, the convenience and value of such devices are diminished as a consequence of the need for regular battery replacement. Existing wireless input devices are also frequently of limited range and the wireless link established for communication with the host computer is often rather unreliable and/or exhibits a high latency. In addition, such wireless links are often relatively insecure and thus susceptible to eavesdropping or unauthorized monitoring.